DESCRIPTION: The objective of this proposal is to understand the catalytic, structural, and cell biological features of fatty acid amide hydrolase (FAAH), a mammalian membrane-bound enzyme responsible for the catabolism of the fatty acid amide family of endogenous signaling lipids. Representative fatty acid amides degraded by FAAH include the endocannabinoid anandamide and the sleep-inducing lipid oleamide. Fatty acid amides have been shown to induce a remarkable array of pharmacological effects in mammals, including sleep, analgesia, hypothermia, and learning and memory defects. The impressive bioactivity of fatty acid amides suggests that FAAH might serve as an attractive target for therapeutic efforts aimed at influencing pain, sleep, and memory systems. The elucidation of FAAH's catalytic, structural, and cellular features would provide a foundation for the design of FAAH-specific chemical inhibitors to be employed as agents for both the study of fatty acid amide-based physiological processes and the potential pharmaceutical treatment of pathologies associated with these systems. In this application, the molecular and cellular properties of FAAH will be examined using a multidisciplinary approach, employing biochemistry, molecular biology, immunochemistry, and synthetic chemistry techniques towards the goals of determining: 1) the catalytic mechanism and origins of substrate selectivity for FAAH-mediated amide hydrolysis, 2) the x-ray crystal structure of a FAAH-oleyl phosphonate inhibitor complex, 3) the domains of FAAH responsible for self-association and membrane binding, and 4) the cellular and subcellular localization of FAAH in mammalian tissue. These proposed studies should provide molecular tools for the chemical and genetic regulation of FAAH in vivo, allowing for a direct evaluation of the potential costs and benefits of therapeutic strategies that target the endocannabinioid system for the treatment of pain, sleep, and/or mood disorders.